[Backport 2.x] Change log level of SegRep cancellations to debug

[opensearch-trigger-bot]

Backport 628bbd0 from #9445.

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: SUCCESS ✅
• URL: https://build.ci.opensearch.org/job/gradle-check/23077/
• CommitID: 4bf2aa4

[codecov]

Codecov Report

Merging #9451 (4bf2aa4) into 2.x (c7fcd71) will increase coverage by 0.02%.
The diff coverage is 61.53%.

@@             Coverage Diff              @@
##                2.x    #9451      +/-   ##
============================================
+ Coverage     70.73%   70.76%   +0.02%     
+ Complexity    57551    57542       -9     
============================================
  Files          4762     4762              
  Lines        272083   272085       +2     
  Branches      40110    40110              
============================================
+ Hits         192470   192528      +58     
+ Misses        63110    63035      -75     
- Partials      16503    16522      +19     

Files Changed	Coverage Δ
...s/replication/SegmentReplicationTargetService.java	56.75% <61.53%> (-1.88%)	⬇️

... and 467 files with indirect coverage changes